1. Field of the Invention
The present invention relates to a steam blower box unit having a steam blower box for applying steam to a passing material web, especially a paper or board web, and, more particularly, the present invention also relates to a method for moving a steam blower box out of its operating position.
2. Description of the Related Art
Steam blower boxes are used in papermaking. They are used in particular to increase the temperature of the material web with the aid of the steam applied to the material web, in order to improve the dewatering of the material web. In this case, a respective steam blower box offers the possibility of influencing the cross-machine moisture profile of the material web by way of the sectional application of steam transversely with respect to the web running direction. Such a steam blower box is described, for example, in WO 99/41450.
Hitherto, withdrawal rails and a withdrawal carriage have generally been used for a respective removal of the entire steam blower box. However, such a removal is relatively time-consuming and entails specific expenditure on additional parts. Such a method is problematic, in particular in installations having a guide roll which cannot be lowered.
It has been proposed to withdraw only the internal fittings of the steam blower box, including valves and zone chambers. Since, in this case, the housing having the steam outlet holes remains within the papermaking machine, these are accessible only with difficulty for cleaning.
What is needed in the art is an improved steam blower box unit and an improved method of moving the steam blower box with which rapid withdrawal, for example within one hour, and complete maintenance are ensured, in which cleaning of all the regions of the steam blow box and rapid replacement of defective parts is possible without difficulty.